ESL systems typically include a plurality of ESLs for each merchandise item in a store. ESLs display the price of corresponding merchandise items on store shelves and are typically attached to a rail along the leading edge of the shelves. A store may contain thousands of ESLs to display the prices of the merchandise items. The ESLs are coupled to a central server where information about the ESLs is typically maintained in an ESL data file which contains ESL identification information and ESL merchandise item information. The central server sends messages, including price change messages, to the ESLs.
While prior ESL systems provide many of the capabilities required by retailers, these systems may suffer from various disadvantages. For example, while communication between the central server and the ESLs is quite reliable, occasionally noise or other interference cause the central server to detect a particular response when another response, or no response at all, was transmitted by the ESL. Such an error may cause the central server to believe an ESL is correctly displaying information, when in actuality the ESL is not displaying the correct information. Therefore, it would be desirable to provide an ESL system and method that automatically detects ESL communication errors which result in the ESL containing incorrect data in the ESL's registers, and then automatically takes corrective action to update the ESL's memory with the correct data.